   "Passes on events only when their metric falls outside the given (inclusive)
   range."
   [r & children]
-  (fn [event]
+  (fn stream [event]
     (when-let [m (:metric event)]
       (when-not (<= (first r) m (last r))
         (call-rescue event children)))))

        children (if (map? options)
                   (rest children)
                   children)]
    (fn [event]
      (when
        (dosync
          (let [cur (pred event)

                          (alter bins assoc start bin)
                          (finish-eventually bin start))))))))]

    (fn stream [event]
      (let [; What time did this event happen at?
            t (or (:time event) (unix-time))]
        (bin event t)))))
